Surgical stapling device

ABSTRACT

A surgical stapling device for applying an array of surgical staples to tissue is provided. The stapling device includes an approximation mechanism for moving a cartridge assembly and an anvil assembly between spaced and approximated positions and a firing mechanism for ejecting the array of staples from the cartridge assembly. A single trigger is operable to effect approximation and firing of the device. The device also includes an alignment pin assembly which can be selectively manually or automatically advanced. The anvil assembly includes a stiffener plate which allows the device to have a reduced head portion profile.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/436,282 filed May 18, 2006, which is a continuation of U.S.patent application Ser. No. 11/125,790, filed on May 10, 2005 nowabandoned, which is a continuation of U.S. patent application Ser. No.10/783,126 filed on Feb. 20, 2004, now abandoned, which is acontinuation of U.S. patent application Ser. No. 09/687,815, filed onOct. 13, 2000, now U.S. Pat. No. 6,817,508. The entire contents of eachof these prior applications is incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates generally to a surgical staplingapparatus and, more specifically, to a surgical stapling apparatushaving a single trigger for approximating anvil and cartridge assembliesand for ejecting an array of staples from the cartridge assembly.

2. Background of Related Art

Surgical stapling instruments used for applying parallel rows of staplesthrough compressed living tissue are well known in the art, and arecommonly used, for example, for closure of tissue or organs prior totransection, prior to resection, or in anastomoses, and for occlusion oforgans in thoracic and abdominal procedures.

Typically, such surgical stapling instruments include an anvil assembly,a cartridge assembly for supporting an array of surgical staples, anapproximation mechanism for approximating the anvil and cartridgeassemblies, an alignment pin assembly for capturing tissue between thecartridge and anvil assemblies and for maintaining alignment between thecartridge and anvil assemblies during approximation and firing, and afiring mechanism for ejecting the surgical staples from the cartridgeassembly. The approximation mechanism and the firing mechanism generallyinclude distinct actuators for effecting approximation and firing of thestaples. The alignment pin assembly can be manually operated to advancean alignment pin from the cartridge assembly into engagement with theanvil or, alternatively, the alignment pin assembly can be automaticallyactuated upon operation of the approximation mechanism. In instrumentshaving a manually operated alignment pin assembly, the actuator for thealignment pin assembly is disposed at a location spaced from the handleof the instrument.

U.S. Pat. No. 4,930,503 to Pruitt discloses such a surgical staplinginstrument. Pruitt's instrument includes a manually operated alignmentpin assembly, an approximation mechanism including a rotatable knobactuator and a firing mechanism including a pivotable trigger. In use, asurgeon must first approximate the anvil and cartridge members byrotating the knob actuator. Next, the surgeon can advance the alignmentpin assembly by advancing a knob supported on the central body portionof the instrument. Thereafter, the instrument can be fired by pivotingthe trigger towards a stationary handle of the instrument.

U.S. Pat. No. 5,697,543 to Burdorff also discloses a surgical staplinginstrument having an approximation mechanism, a firing mechanism and analignment pin mechanism. The approximation and firing mechanisms eachinclude a distinct pivotable trigger actuator. The alignment pinmechanism is operatively associated with the approximation mechanismsuch that upon actuation of the approximation mechanism, the alignmentpin assembly is automatically advanced.

Known prior art surgical staplers are lacking in several respects.Firstly, the use of multiple actuators to effect approximation andfiring of the instruments complicate the manufacture and operation ofthe instrument and, in most cases, require the surgeon to use two handsto hold and operate the instrument. Secondly, the instruments in whichthe alignment pin assembly is operatively associated with theapproximation mechanism require that the instrument be approximated toadvance the alignment pin assembly, despite the fact that a surgeon mayprefer to advance the alignment pin assembly prior to approximation. Incontrast, the instruments in which the alignment pin assembly ismanually advanced typically require the surgeon to use a second hand toactuate the alignment pin assembly.

Accordingly, a continuing need exists in the surgical art for a surgicalstapling instrument which can be operated by a surgeon with a singlehand and which includes an alignment pin assembly which can beautomatically or manually advanced.

SUMMARY

In accordance with the present disclosure, a surgical stapling device isprovided which includes a frame having a proximal end and a distal end.A body defining a stationary handle is secured to the proximal end ofthe frame. A head portion including an anvil assembly and a cartridgeassembly are supported on the distal end of the frame. The anvil andcartridge assemblies are movable in relation to each other betweenspaced and approximated positions. An approximation mechanism includes aclamp slide assembly having a distal end configured to support thecartridge assembly and a proximal end. A firing mechanism includes athrust bar having a distal end positioned to be slidably received withinthe cartridge assembly. A pivotable trigger is supported on the body andis operably associated with the approximation mechanism and the firingmechanism such that the trigger is pivotable through an approximationstroke to approximate the anvil and cartridge assemblies and,subsequently, pivotable through a firing stroke to eject an array ofstaples from the cartridge assembly.

The presently disclosed surgical stapling device also has an alignmentpin assembly which includes an alignment pin, a pin pusher and a bellcrank. The alignment pin pusher is slidably supported on the framebetween advanced and retracted positions. The alignment pin pusherincludes a distal abutment member for engaging and advancing thealignment pin from a retracted position located within the cartridgeassembly to an advanced position engaging the anvil assembly. The bellcrank is operably connected to the clamp slide assembly and isreleasably coupled to the pin pusher. Upon advancement of the clampslide assembly, the bell crank is pivoted to concurrently advance thealignment pin pusher. The alignment pin pusher includes a pair of postswhich extend through slots in the body. A thumb button is supported oneach post. The thumb button(s) can be pushed prior to approximation ofthe device to manually advance the alignment pin assembly intoengagement with the anvil assembly. The thumb buttons are positioned onthe body such that a surgeon is able to manually advance the alignmentpin assembly using the same hand that actuates the pivotable trigger.

A pawl mechanism is supported in the body and includes a clamping pawland a firing pawl. The clamping pawl functions to prevent return of theapproximation mechanism after the trigger has moved throughapproximately three quarters of the approximation stroke. The clampingpawl also provides an audible and tactile indication that the device hasbeen moved to the approximately three quarter approximated position. Thefiring pawl functions to provide an audible indication that the deviceis in a fire-ready position. The firing pawl also functions to lock thetrigger in a compressed position after firing of the device has occurredto provide a visual indication that firing has occurred. A releasebutton is provided to return the approximation mechanism to theretracted position at any point of operation of the device. Thepivotable trigger, the release button and the thumb button are alldisposed adjacent the handle portion of the device and are operable bythe surgeon using a single hand.

The anvil assembly of the surgical stapling device is provided with astiffener plate to provide increased strength to the assembly. By usingthe stiffener plate, the head portion profile can be reduced in sizewithout reducing the overall strength of the anvil assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed surgical stapling apparatus aredescribed herein with reference to the drawings, wherein:

FIG. 1 is a perspective view of one embodiment of the presentlydisclosed surgical stapling device;

FIG. 2 is a side view of the surgical stapling device shown in FIG. 1;

FIG. 3 is a top view of the surgical stapling device shown in FIG. 1;

FIG. 4 is a perspective view with parts separated of the surgicalstapling device shown in FIG. 1;

FIG. 5 is a perspective view of the surgical stapling device shown inFIG. 1 with the left body half-section removed from the handle portionof the device;

FIG. 6 is a perspective view of the handle portion of the surgicalstapling device shown in FIG. 7 with the left body half-section removedand a portion of the frame cutaway;

FIG. 7 is an enlarged view of the indicated area of detail shown in FIG.4;

FIG. 8 is a rear perspective view of the staple pusher assembly of thesurgical stapling device shown in FIG. 7;

FIG. 8A is a rear perspective view of the staple pusher assembly shownin FIG. 8 with parts separated;

FIG. 8B is a perspective view of an alternate embodiment of the staplepusher assembly shown in FIG. 8 with parts separated;

FIG. 8C is a perspective view of the staple pusher assembly shown inFIG. 8B assembled;

FIG. 9 is an enlarged perspective view of the distal end of the surgicalstapling device shown in FIG. 1;

FIG. 9A is an enlarged view of the indicated area of detail shown inFIG. 9;

FIG. 9B is a cross-sectional view taken along section lines 9B-9B ofFIG. 9A;

FIG. 10 is a perspective view from one side of the firing pawl of thesurgical stapling device shown in FIG. 1;

FIG. 10A is a perspective view from the other side of the firing pawlshown in FIG. 10;

FIG. 10B is a perspective view from one side of the cam engagementmember of the surgical stapling device shown in FIG. 4;

FIG. 10C is a perspective view from the other side of the cam engagementmember shown in FIG. 10B;

FIG. 10D is a side perspective view from the bottom of the releasebutton of the surgical stapling device shown in FIG. 4;

FIG. 10E is a bottom perspective view of the release button shown inFIG. 10D;

FIG. 10F is a side perspective view of the proximal portion of thehandle portion with the left body half-section and the release buttonremoved;

FIG. 11 is a perspective view from one side of the clamping pawl of thesurgical stapling device shown in FIG. 1;

FIG. 11A is a perspective view from the other side of the clamping pawlshown in FIG. 11;

FIG. 12 is a perspective view with parts separated of the trigger andfiring link of the surgical stapling device shown in FIG.1;

FIG. 13 is a perspective view with parts separated of the release buttonassembly and bi-linkage assembly of the surgical stapling device shownin FIG. 1;

FIG. 14 is a perspective view with parts separated of the pin pusher andbell crank of the surgical stapling device shown in FIG. 1;

FIG. 14A is an enlarged view of the indicated area of detail shown inFIG. 14;

FIG. 14B is a perspective view of another embodiment of a pin pusheraccording to the present disclosure;

FIG. 15 is a side cross-sectional view of the surgical stapling devicetaken along section lines 15-15 of FIG. 3;

FIG. 15A is a side partial cutaway view of the handle portion of thesurgical stapling device shown in FIG. 1 with the left body half-sectionremoved;

FIG. 15B is an enlarged view of the indicated area of detail shown inFIG. 15;

FIG. 15C is an enlarged view of the indicated area of detail shown inFIG. 15A;

FIG. 15D is an enlarged view of the indicated area of detail shown inFIG. 15;

FIG. 15E is a side cross-sectional view of the proximal portion of thehandle portion of the surgical stapling device shown in FIG. 1 takenthrough the release mechanism prior to actuation of the surgicalstapling device;

FIG. 15F is a top perspective view of the proximal portion of the handleportion of the surgical stapling device shown in FIG. 1 prior toactuation with the left body half-section removed;

FIG. 16 is a side cross-sectional view of the surgical stapling deviceshown in FIG. 1 during approximation of the anvil and cartridgeassemblies;

FIG. 16A is a side partial cutaway view of the handle portion of thesurgical stapling device shown in FIG. 1 during approximation of theanvil and cartridge assemblies with the left body half-section removedfrom the handle portion of the device;

FIG. 16B is an enlarged view of the indicated area of detail shown inFIG. 16;

FIG. 16C is an enlarged view of the indicated area of detail shown inFIG. 16A.

FIG. 17 is a side cross-sectional view of the surgical stapling deviceshown in FIG. 1 in the approximated position with the trigger in thecompressed position;

FIG. 17A is a side partial cutaway view of the handle portion of thesurgical stapling device shown in FIG. 1 in the approximated positionwith the left body half-section removed, a proximal portion of the framecutaway and the trigger in the compressed position;

FIG. 17B is an enlarged view of the indicated area of detail shown inFIG. 17;

FIG. 17C is an enlarged view of the indicated area of detail shown inFIG. 17A.

FIG. 18 is a side cross-sectional view of the surgical stapling deviceshown in FIG. 1 in the approximated position with the trigger in afire-ready position;

FIG. 18A is a side partial cutaway view of the handle portion of thesurgical stapling device shown in FIG. 1 in the fully approximatedposition with the left body half-section removed, a proximal portion ofthe frame cutaway and the trigger in a fire-ready position;

FIG. 18B is an enlarged view of the indicated area of detail shown inFIG. 18;

FIG. 18C is an enlarged view of the indicated area of detail shown inFIG. 18A.

FIG. 19 is a side cross-sectional view of the surgical stapling deviceshown in FIG. 1 after the device has been fired with the trigger in acompressed and locked position;

FIG. 19A is a side partial cutaway view of the handle portion of thesurgical stapling device shown in FIG. 1 in the fired position with theleft body half-section and frame removed from the handle portion of thedevice and the trigger in the compressed position;

FIG. 19B is an enlarged view of the indicated area of detail shown inFIG. 19;

FIG. 19C is an enlarged view of the indicated area of detail shown inFIG. 19A;

FIG. 19D is a side cross-sectional view of the proximal portion of thehandle portion of the surgical stapling device shown in FIG. 19A takenthrough the release mechanism during operation of the release buttonassembly;

FIG. 19E is a top perspective view of the proximal portion of the handleportion shown in

FIG. 19D;

FIG. 19F is a side view of the proximal portion of the handle portionshown in FIG. 19D with the left frame member removed;

FIG. 20 is a side cross-sectional view of the surgical stapling deviceshown in FIG. 1 after the staples have been fired from the staplecartridge and the cartridge assembly has been moved to the retractedposition;

FIG. 20A is an enlarged view of the indicated area of detail shown inFIG. 20;

FIG. 21 is a top view of tissue illustrating the staple configurationapplied to tissue by the surgical stapling device shown in FIG. 1; and

FIG. 22 is a top view of the tissue shown in FIG. 16 illustrating thestaple configuration after the tissue has been cut.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the presently disclosed surgical stapling device will nowbe described in detail with reference to the drawings, wherein likereference numerals designate identical or corresponding elements in eachof the several views.

The presently disclosed surgical stapling device shown generally as 10in FIGS. 1-3 includes a body 12 defining a stationary handle 14, apivotable trigger 16, an elongated central body portion 18, a cartridgeassembly 20 and an anvil assembly 22. A thumb button 24 is slidablypositioned on each side of body 12. Thumb buttons 24 are movable tomanually advance an alignment pin assembly in a manner to be describedin detail below. A release button 150 of a release mechanism 26 (FIG.13) is positioned on the proximal end of body 12 and is depressible toallow cartridge assembly 20 to return from an approximated positiondisposed adjacent to anvil assembly 22 to a position spaced from anvilassembly 22 (as shown). Operation of release mechanism 26 will also bedescribed in detail below.

Referring to FIG. 4, body 12 is formed from a pair of moldedhalf-sections 12 a and 12 b. In one embodiment, half-sections 12 a and12 b are formed of plastic, although other materials including metalsmay be used to form the half-sections. A cushioned gripping member 14 ais secured to stationary handle 14 of each half-section 12 a and 12 b.Gripping member 14 a may be formed by injection molding a thermoplasticelastomer, such as VERSAFLEX™ or SANTOPRENE™, to stationary handle 14.Alternately, cushioned gripping member 14 can be formed on or secured tostationary handle 14 using any known fastening technique includingadhesives, screws, welding, overmolding, etc. A pair of spaced framemembers 28 a and 28 b extends between housing half-sections 12 a and 12b and anvil assembly 22. A central portion of frame members 28 a and 28b form elongated central body portion 18. Frame members 28 a and 28 bmay be formed of a surgical grade metal such as stainless steel.Alternately, other suitable materials meeting the requisite strengthrequirements may also be used.

Referring also to FIGS. 9-9B, anvil assembly 22 includes a stiffenerplate 30, a spacer plate 32, a T-track 34, and an anvil 36. An opening67 (FIG. 9A) is formed in anvil 36 to allow passage of alignment pin 38of cartridge assembly 20. Stiffener plate 30 has a vertical portion 30 aand a horizontal portion 30 b. A notch 30 c is formed in the distal endof vertical portion 30 a and is configured to receive the tip 38 a of acartridge alignment pin 38. Horizontal portion 30 b of plate 30 includesa cutout 40 dimensioned to receive an interlock member 42 which will bediscussed in further detail below. In the assembled state, a distalvertical portion of frame members 28 a and 28 b are positioned onopposite sides of vertical portion 30 a of stiffener plate 30. Spacerplate 32 includes a pair of legs which are positioned on opposite sidesof stiffener plate 30 between stiffener plate 30 and anvil 36 (FIG. 9B).Anvil 36 defines a channel 36 a (FIG. 4) and is positioned about spacerplate 32. A cap 39 is positioned over a distal end of anvil assembly 22to provide a smoother surface which is less likely to snag tissue duringuse. Cap 39 includes a groove 39 a which defines one end of a cuttingguide slot 41 formed between anvil 36 and frame member 28 b. Groove 39 aand cutting guide slot 41 facilitate cutting of tissue with a scalpelafter device 10 has been fired.

T-track 34 defines a through slot 45. Slot 45 is positioned overhorizontal portion 30 b of stiffener plate 30 between frame members 28 aand 28 b. T-track 34 is positioned about cutout 40 to define a cavity inwhich interlock 42 is positioned. In one embodiment, the anvil assemblycomponents and frame members 28 a and 28 b are secured together usingrivets 44. Alternately, other fastening members or techniques may beused to secure the anvil assembly components and the frame memberstogether including screws, pins, welding, etc. In one embodiment, thecomponents of anvil assembly 22 are formed of stainless steel.Alternately, other materials, including metals having requisite strengthrequirements can be used to form some or all of the anvil components.

Referring to FIGS. 9 and 9A, anvil 36 includes a plurality of staplepockets 37 formed in the surface of anvil 36. Each staple pocket 37includes first and second staple forming cups 37 a and 37 b and achanneling surface 37 c disposed around each staple forming cup 37 a. Ananvil including such a staple forming pocket has been disclosed in U.S.Pat. No. 5,480,089 filed Aug. 19, 1994, the entirety of which isincorporated herein by reference.

Referring to FIGS. 4 and 7-8A, cartridge assembly 20 includes acartridge 50 having an array of staple receiving slots 52. A staplepusher assembly 54 includes a plurality of pusher members 58. Eachpusher member 58 includes a plurality of fingers 58 a configured to beslidably received within a respective staple receiving slot 52. Fingers58 a are positioned behind staples 56 in slots 52 such that advancementof fingers 58 a effects ejection of staples 56 from slots 52. A guidechannel 60 (FIG. 15) formed in cartridge 50 is configured to slidablyreceive alignment pin 38 (FIG. 4). A spring 64 is positioned about pin38 to urge alignment pin 38 to a retracted position within guide channel60. An opening 65 formed in cartridge 50 allows alignment pin 38 toextend from guide channel 60 through anvil opening 67 (FIG.9A) intonotch 30 c formed in anvil assembly 22. Operation of the alignment pinmechanism for advancing alignment pin 38 will be described in detailbelow.

Referring also to FIGS. 8B and 8C, staple pusher assembly 54 includesmultiple pusher members 58 which interengage to form pusher assembly 54.Pusher assembly 54 may be modified by adding or subtracting pushermembers 58 to accommodate different size cartridges. For example, apusher member 58 can be removed from the assembly such as shown in FIGS.8B and 8C to accommodate a smaller cartridge assembly.

Referring to FIGS. 4 and 5, surgical stapling device 10 includes a pairof clamp slide members 66 a and 66 b, an alignment pin pusher 68 and athrust bar 70. Clamp slide members 66 a and 66 b, alignment pin pusher68 and thrust bar 70 are slidably supported between frame members 28 aand 28 b for movement between retracted and advanced positions inresponse to movement of trigger 16 through an approximation strokeand/or a firing stroke. Operation of each of the above members will bedescribed in detail below.

Clamp slide members 66 a and 66 b form part of the approximationmechanism of the surgical stapling device. Each clamp slide member has adistal end 72, a proximal end 74 and an elongated body 76. Elongatedbody 76 includes a pair of elongated guide slots 78 a and 78 b. Guideslots 78 a and 78 b are dimensioned to slidably receive pins 80 a and 80b (FIG. 15), respectively, which extend between frame members 28 a and28 b. The positioning of pins 80 a and 80 b in guide slots 78 a and 78 bfunctions to maintain alignment between clamp slide members 66 a and 66b and frame members 28 a and 28 b during movement between the advancedand retracted positions and to limit the extent of longitudinal movementof clamp slide members 66 a and 66 b, i.e., the fully advanced positionof the clamp slide members is reached when the proximal end of slot 78 aengages pin 80 a and the fully retracted position of the clamp slidemembers is reached when the distal end of slot 78 a engages pin 80 a.

Distal end 72 of each clamp slide member 66 a and 66 b includes a headportion 82. Each head portion 82 has a plurality of openings 84configured to receive a fastening member 86 (FIG. 5) for securing clampslide members 66 a and 66 b together in spaced relation. In theassembled state, clamp slide members 66 a and 66 b are spaced from eachother to define an elongated channel in which pin pusher 68 and thrustbar 70 are slidably disposed. Distal end 72 of clamp slide members 66 aand 66 b define a cartridge support receptacle for receiving cartridgeassembly 20. A series of dimples 85 on each of clamp slide members 66 aand 66 b function to frictionally retain cartridge assembly 20 withinthe cartridge support receptacle. Proximal end 74 of clamp slide members66 a and 66 b each include a hole 87 for receiving a pin 88 of theactuation assembly which will be described in detail below.

Referring also to FIG. 14, alignment pin pusher 68 defines a channel 69along its length which is dimensioned to slidably receive thrust bar 70.Alignment pin pusher 68 includes a vertical portion 90 having anabutment member 91 configured to engage the proximal end 38 b (FIG. 4)of alignment pin 38 such that when alignment pin pusher 68 is moved toan advanced position (in the manner described below), alignment pin 38is advanced from within cartridge 50 through opening 65 in cartridge 50and opening 67 in anvil 36 into notch 30 c of anvil assembly 22.Alignment pin pusher 68 includes a pair of elongated slots 92 a and 92b. Pins 80 a and 80 b (FIG. 15) extend through slots 92 a and 92 b,respectively, to guide alignment pin pusher 68 during movement betweenthe advanced and retracted positions. The proximal end of alignment pinpusher 68 includes a pair of spaced legs 68 a and 68 b. Each leg 68 aand 68 b includes a radially extending post 120 which is dimensioned toextend through elongated slots 122 (FIG. 4) formed in body half-sections12 a and 12 b. Thumb buttons 24 are fastened to posts 120 to facilitatemanual actuation of alignment pin pusher 68.

A resilient clip 126 defining a receptacle 127 is formed on alignmentpin pusher 68 and is dimensioned to releasably receive link 94 of bellcrank 96. In one embodiment, the resilient clip 126 is substantiallyC-shaped and includes an angled guide portion 126 a (FIG. 14 a) fordirecting link 94 into receptacle 127. Alternately, other releasableengaging structures may be used. Operation of bell crank 96 and thehandle actuation assembly will be described in detail below.

Referring now to FIG. 14B, an alternate embodiment of the pin pusher isillustrated and referenced generally as 168. Alignment pin pusher 168includes the same or substantially similar components as does alignmentpin pusher 68, with the differences therebetween discussed in detailhereinafter. Alignment pin pusher 168 includes legs 168 a and 168 b thatare spaced apart and located at a proximal end of alignment pin pusher168. Instead of providing the legs with a substantially uniform heightdimension as in legs 68 a, 68 b (FIG. 14), legs 168 a, 168 b have acontoured profile. Each contour has a maximum height dimension at theproximal and distal end regions of each leg 168 a, 168 b. Adjacent tothe distal end region of each leg 168 a, 168 b, the contour tapers to aminimum height dimension and subsequently increases to an intermediateheight dimension disposed distally of the proximal end region. Each leg168 a and 168 b includes a radially extending post 120 which isdimensioned to extend through elongated slots 122 (FIG. 4) formed inbody half-sections 12 a and 12 b. In addition, each leg 168 a, 168 bincludes a rib 166 disposed thereon, wherein each rib 166 extends alonga longitudinal axis of its respective leg.

By providing a contoured profile on each leg 168 a, 168 b, the mass ofalignment pin pusher 168 is reduced even though alignment pin pusher 168includes ribs 166. In comparison to alignment pin pusher 68, alignmentpin pusher 168 absorbs less energy, thereby reducing the noise generatedby the engagement of bell crank 96 and alignment pin pusher 168 aftermanual adavancement of alignment pin pusher 168.

Referring again to FIG. 4, thrust bar 70 is slidably positioned withinchannel 69 defined within alignment pin pusher 68. The distal end ofthrust bar 70 includes an engagement head 100 configured to engagestaple pusher assembly 54. Thrust bar 70 also includes a pair ofelongated slots 102 a and 102 b which are dimensioned to slidablyreceive pins 80 a and 80 b (FIG. 15). As discussed above with respect toclamp slide members 66 a and 66 b, pins 80 a and 80 b function not onlyto guide the movement of thrust bar 70 between the retracted andadvanced positions, but also to define the fully advanced and fullyretracted positions of thrust bar 70. As illustrated in FIG. 15, slots102 a and 102 b in thrust bar 70 are longer than slots 78 a and 78 bformed in clamp slides 66 a and 66 b, respectively. The increased lengthof slots 102 a and 102 b permit thrust bar 70 to be advanced distallyfrom the approximated position independently of clamp slides 66 a and 66b through cartridge assembly 20 to eject staples from cartridge assembly20. The proximal end of thrust bar 70 is adapted to engage a biasingmember 71 which is supported in tension between frame 28 a and thrustbar 70 to urge thrust bar 70 to the retracted position. The proximal endof thrust bar 70 also includes a notch 104 which is configured toreceive the distal end of a firing link 106 and will be discussed infurther detail below.

Referring to FIGS. 4-6, and 10-13, a handle actuation assembly includespivotable trigger 16, a bi-linkage assembly 111 including a front link112 and a rear link 114, bell crank 96, firing link 106, a clamping pawl108 and a firing pawl 110. Release mechanism 26 includes a releasebutton 150, a release lever 152 and a release or cam engagement member153 provided within body 12.

Pivotable trigger 16 is pivotably secured between body half-sections 12a and 12 b about pivot members 116 which are integrally formed onopposite sides of trigger 16. Alternately, a pivot pin can be used topivotally support trigger 16 between the body half-sections. Trigger 16includes a cushioned grip 16 a, which may be secured to trigger 16 inthe manner discussed above with respect to stationary handle 14, and arearward extension 115 positioned beneath bi-linkage assembly 111. Inone embodiment, cushioned grip 16 a includes a plurality of spacedprotrusions 16 b to provide enhanced slip resistance. Rear link 114 ofbi-linkage assembly 111 has a rear end pivotally secured about pivot pin113 which extends between body members 12 a and 12 b and a forward endpivotably fastened to the rear end of front link 112 by pivot pin 118.It is noted that release button 150 is also pivotally secured to pivotpin 113. The forward end of front link 112 is pivotally fastened toclamp slide members 66 a and 66 b by pin 88 and includes a pair ofspaced slots 112 a and 112 b separated by a spacer 112 c (FIG. 13).Spaced slots 112 a and 112 b are dimensioned to receive the proximalends of clamp slide members 66 a and 66 b. Spacer 112 c maintains thecorrect spacing between clamp slide members 66 a and 66 b. When trigger16 is pivoted about pivot members 116, rearward extension 115 of trigger16 urges bi-linkage assembly 111 from a position in which thelongitudinal axes of front and rear links 112 and 114 are misaligned toa position in which the axes of front and rear links 112 and 114 aresubstantially aligned. In the substantially aligned position, links 112and 114 are moved to an overcenter position slightly past actualalignment. By moving the bi-linkage assembly slightly overcenter or pastthe aligned position, bi-linkage assembly 111 will not return to themisaligned position until engaged by the release mechanism 26. Since therear end of rear link 114 is fastened within body 12, as bi-linkageassembly 111 is moved from its misaligned position to its alignedposition, front link 112 is advanced distally to advance clamp slidemembers 66 a and 66 b distally. Advancement of clamp slide members 66 aand 66 b effects corresponding advancement of cartridge assembly 20 toeffect approximation of anvil and cartridge assemblies 22 and 20,respectively.

Referring to FIGS. 4 and 15, thrust bar 70 includes a forward elongatedslot 103. Rivets 117, which extend between clamp slide members 66 a and66 b, also extend through slot 103. When clamp slide members 66 a and 66b are advanced from a retracted position to an advanced position, rivets117 engage the forward end of slot 103 to advance thrust bar 70concurrently with clamp slide members 66 a and 66 b. As illustrated inFIG. 15, slot 103 is of a length to allow thrust bar 70 to advancedistally beyond the approximated position independently of clamp slidemembers 66 a and 66 b.

Referring to FIGS. 4 and 14, bell crank 96 is pivotably secured betweenframe members 28 a and 28 b by pivot member 134. As discussed above,link 94 of bell crank 96 is releasably positioned within clip 126 ofalignment pin pusher 68. Bell crank 96 includes a pair of spacedsidewalls 96 a and 96 b. Each sidewall 96 a and 96 b includes aninwardly extending cam member 138 which is configured to be receivedwithin a cam slot 140 formed in the proximal end of clamp slides 66 aand 66 b. As clamp slides 66 a and 66 b are advanced distally, the wallsdefining cam slots 140 engage cam members 138 to pivot bell crank 96about pivot member 134. When bell crank 96 is pivoted, post 94 urges pinpusher 68 distally to advance abutment member 91 through guide channel60 to advance alignment pin 38 into engagement with anvil assembly 22.Cam slots 140 are configured to quickly pivot bell crank 96 during theinitial advancement of clamp slides 66 a and 66 b such as to quicklyadvance alignment pin pusher 68 and alignment pin 38 during the initialstage of approximation. In one embodiment, cam slots 140 are configuredto effect full advancement of alignment pin 38 after only about 50%advancement of clamp slides 66 a and 66. Alternately, other cam slotconfigurations are envisioned which increase or decrease the advancementrate of the clamp slide members.

Referring again to FIGS. 4 and 13, release mechanism 26 includes releasebutton 150, release lever 152 and a release or cam engagement member153. As discussed above, release button 150 includes a rear end which ispivotally secured to pivot pin 113. A biasing member or torsion spring204 (FIG. 13) urges release button 150 upwardly. Pivot pin 113 issecured between body members 12 a and 12 b. The forward end of releasebutton 150 includes a slot 154 dimensioned to slidably receive a rod 156formed on a rear end of release lever 152. The forward end of releaselever 152 is pivotally secured between body half-sections 12 a and 12 babout a pivot member 152 a. An engagement member 158 projects downwardlyfrom the bottom of release lever 152 and is positioned to abutbi-linkage assembly 111 when release button 150 is depressed to urgebi-linkage assembly 111 from the substantially aligned overcenterposition to the misaligned position.

Referring to FIGS. 10A-10F, release or cam engagement member 153includes first and second wings 153 a and 153 b and is pivotally securedto release button 150 about a rod or pin 210. Pin 210 extends betweenopenings 212 defined in a proximal end of release button 150. First wing153 a is positioned to engage a top surface of frame member 28 b.Torsion spring 204, is positioned about a hub 153 c between releasebutton 150 and second wing 153 b to urge release button 150 upwardly(clockwise in FIG. 15E) and cam engagement member 153 downwardly(counter-clockwise in FIG. 15E). Engagement between first wing 153 a andthe top surface of frame member 28 b limits downward movement of camengagement member 153. Cam engagement member 153 functions to effectpivoting of firing pawl 110 to release trigger 16 after device 10 hasbeen fired as will be discussed in further detail below.

Referring to FIGS. 4, 10, 10A, 11, and 11A, surgical stapling apparatus10 includes a pawl assembly including clamping pawl 108 and firing pawl110. Clamping pawl 108 is pivotably secured about pivot member 170 insemi-circular slot 172 (FIG. 4) in frame 28 a. A spring 174 is securedbetween clamping pawl 108 and frame 28 a to urge clamping pawl 108 torotate in a clockwise direction as viewed in FIG. 4. Clamping pawl 108includes a cam surface 176 having a recess 178 positioned to engage cammember 180 (FIG. 16B) formed on extension 115 of trigger 16. When cammember 180 on trigger 16 is positioned in recess 178 of cam surface 176(this occurs after the clamp slides 66 a and 66 b have been movedthrough approximately three quarters of the approximation stroke),trigger 16 is prevented from being returned by spring 182 to anon-compressed position. Thus, the cartridge assembly 20 and the anvilassembly 22 are maintained in a three quarter approximated position evenwhen trigger 16 is released by the surgeon.

Firing pawl 110 is pivotably secured about pivot member 184 insemi-circular slot 186 (FIG. 4) formed in frame 28 b. Spring 188 issecured between firing pawl 110 and frame 28 b to urge the firing pawlin a clockwise direction as viewed in FIG. 4. Firing pawl 110 includes acam surface 190 having a recess 192 for engaging a cam member 180′formed on a side of extension 115 of trigger 16 opposite cam member 180.During movement of trigger 16 through the firing stroke, cam member 180′is moved into recess 192 to lock trigger 16 in a compressed positionafter firing has been completed. This provides an audible and visualindication to the surgeon that firing has been completed. Additionaloperational details of the pawl assembly will be described in thefollowing description of the operation of surgical stapling device 10.

Operation of the surgical stapling device will now be described indetail with reference to FIGS. 15-20A. It is noted that the movements ofthe various components will be described from the vantage point of oneviewing the instrument as positioned in the referenced FIG.

FIGS. 15-15C illustrate surgical stapling device 10 prior to use. Asillustrated, cartridge assembly 20 and anvil assembly 22 are in spacedrelation, trigger 16 is in the non-compressed position, and clamp slides66 a and 66 b and thrust bar 70 are in the retracted position (note pins80 a and 80 b are positioned in the forward end of slots 78 a and 78 bof clamp slides 66 a and 66 b and slots 102 a and 102 b of thrust bar70). When thrust bar 70 is in the retracted position, the forward end offiring link 106 is positioned forwardly of notch 104 in thrust bar 70.Since link 106 cannot engage notch 104, device 10 cannot be fired inthis position. Alignment pin pusher 68 and alignment pin 38 are also inthe retracted position with post 94 of bell crank 96 engaged with clip126 of alignment pin pusher 68. At this point, a surgeon could manuallyadvance alignment pin pusher 68 and alignment pin 38 by pushing thumbbutton(s) 24 (FIG. 1) towards the forward end of slots 122 formed inbody halves 12 a and 12 b. This operation would disengage post 94 fromclip 126.

As illustrated in FIGS. 15D-15F, cam engagement member 153 is urgeddownwardly and release button 150 is urged upwardly by torsion spring204. Further, firing pawl 110 is urged to its clockwise-most position byspring 188 (FIG. 4). In this position, if release button 150 is pressed,the distal end 220 of cam engagement member 153 would pass over the topof a lateral projection 216 extending from firing pawl 110 (FIG. 15E).

FIGS. 16-16C illustrate surgical stapling device 10 during theapproximation stroke of trigger 16. As illustrated, trigger 16 is movedin the direction indicated by arrow “A” to move extension 115 of trigger16 in a direction to urge bi-linkage assembly 111 from the misalignedposition towards the substantially aligned position. Because rear link114 is secured to body 12 about pin 113, front link 112 extendsforwardly. Front link 112 is secured to clamp slides 66 a and 66 b bypin 88. As front link 112 is extended forwardly, clamp slides 66 a and66 b are advanced in the direction indicated by arrow “B” in FIG. 16from its retracted position towards its advanced or approximatedposition. Note the position of pins 80 a and 80 b in slots 78 a and 78 band 102 a and 102 b. As discussed above, rivets 117 extend between clampslides 66 a and 66 b through 103 formed in thrust bar 70. As clampslides 66 a and 66 b are advanced, rivet 88 engages the forward end ofslot 103 formed in thrust bar 70 to simultaneously advance thrust bar70. As clamp slides 66 a and 66 b are advanced, engagement between camslots 140 and cam member 138 pivots bell crank 96 about pivot member 134to urge pin pusher 68 distally to advance alignment pin 38 into notch 30c of anvil assembly 22.

Referring also to FIG. 16B, as trigger 16 is pivoted in the directionindicated by arrow “A” (FIG. 16), cam member 180 on extension 115 oftrigger 16 rides up cam surface 176 of clamping pawl 108 to urgeclamping pawl 108 in a counter-clockwise direction against the bias ofspring 174 (FIG. 4). When trigger 16 is pivoted to advance clamp slidemembers 66 a and 66 b through approximately three quarters of theapproximation stroke, cam member 180 snaps into cam recess 178 of camsurface 176 to provide an audible and a tactile indication thatapproximately three quarter approximation has been reached. At thispoint, the positioning of cam member 180 in cam recess 178 preventsspring 182 from returning trigger 16 to the non-compressed positionwithout activating release mechanism 26. Operation of the releasemechanism will be discussed below.

FIGS. 17-17C illustrate the surgical stapling device 10 in the fullyapproximated position with trigger 16 in the compressed position. Asillustrated, extension 115 on trigger 16 has been pivoted to movebi-linkage assembly 111 to the substantially aligned positioned(slightly over-center position) and the clamp slide assembly has beenfully advanced such that cartridge assembly 20 and anvil assembly 22 arein the approximated position. Once again, note the position of pins 80 aand 80 b within clamp slide slots 78 a and 78 b and thrust bar slots 102a and 102 b. Because pins 80 a and 80 b are located at the proximal endof clamp slide slots 78 a and 78 b, only thrust bar 70 can be advancedfurther distally. If the alignment pin pusher 68 was manually advancedprior to approximation disengaging post 94 from clip 126, advancement ofclamp slides 66 a and 66 b to the fully advanced position would movepost 94 of bell crank 96 back into engagement with clip 126. Thus, whenclamp slides 66 a and 66 b were returned to their retracted position,cam slots 140 in clamp slides 66 a and 66 b would pivot bell crank 96 ina direction to move pin pusher 68 to the retracted position.

Referring to FIG. 17B, trigger 16 has been pivoted to remove cam member180 from cam recess 178 in clamping pawl 108. As bi-linkage assembly 111moves overcenter to the substantially aligned position, rear link 114engages abutment member 200 (FIGS. 10-11) formed on clamping pawl 108and firing pawl 110 to rotate the clamping and firing pawlsapproximately 10° counter-clockwise. This rotation removes cam surface176 from the path of cam member 180 of trigger during the return oftrigger 16 to the non-compressed position.

Referring to FIG. 17C, cam member 180′ formed opposite to cam member 180on extension 115 of trigger 16 is now positioned above cam surface 190of firing pawl 110. As trigger 16 is released by the surgeon andreturned to the non-compressed position by spring 182, cam member 180′moves along the backside 190 a of cam surface 190. As cam member 180′reaches the bottom edge of backside 190 a, cam member 180′ moves over anub 220 formed on firing pawl 110. Movement of cam member 180′ over nub220 provides an audible click and a tactile indication that surgicalstapling apparatus 10 is in a fire-ready position.

FIGS. 18-18C illustrate the surgical stapling device 10 in the fullyapproximated position with the trigger 16 in the non-compressedposition. As illustrated, with thrust bar 70 in an advanced position,notch 104 is now aligned with firing link 106 such that movement oftrigger 16 through the firing stroke will effect advancement of thrustbar 70. Referring to FIG. 18C, camming member 180′ is now positionedbelow cam surface 190 of firing pawl 110.

FIGS. 19-19C illustrate surgical stapling instrument 10 after trigger 16has been moved through the firing stroke. As illustrated, thrust bar 70has been advanced distally to eject staples from cartridge assembly 20.Note pins 80 a and 80 b are now positioned adjacent the proximal end ofslots 102 a and 102 b. Referring particularly to FIG. 19C, cam member180′ of extension 115 of trigger 16 has moved up cam surface 190 and ispositioned in recess 192. Engagement between cam member 180′ and recess192 prevents spring 182 from returning trigger 16 to the non-compressedposition to provide a visual indication to the surgeon that the surgicaldevice has been fired. Movement of cam member 180′ into recess 192, alsoprovides an audible indication that firing of the device has occurred.

FIGS. 19D-19F illustrate surgical stapling device 10 after it has beenfired and the release button 150 of release mechanism 26 has beendepressed to return bi-linkage assembly 111 to the misaligned position.As illustrated, when release button 150 is depressed against the urgingof torsion spring 204, cam engagement member 153 is advanced distallysuch that its distal end 220 engages lateral projection 216 on firingpawl 110, and pushes firing pawl 110 in a clockwise direction todisengage cam member 180′ from recess 192 of cam surface 190. In oneembodiment, distal end 220 of cam engagement member 153 and projection216 of firing pawl 110 are angled to guide cam engagement member 153under projection 216. Further, abutment 158 of release lever 152 isurged downwardly into rear link 114 to move bi-linkage assembly 111 backovercenter. Once bi-linkage assembly 111 is moved back overcenter,spring 71 returns thrust bar 70 and clamp slide members 66 a and 66 bproximally to return links 112 and 114 to the misaligned position.

As illustrated in FIG. 20A, interlock 42 is normally urged by pusherassembly 54 to a position located within recess 40. After cartridgeassembly 20 has been fired, pusher assembly 54 is no longer positionedto bias interlock 42 into recess 40. Until a new cartridge has beeninserted into surgical stapling device 10, interlock 42 will extend fromrecess 40 to prevent thrust bar 70 from being advanced distally.

FIG. 21 illustrates tissue 300 having an applied array of staples 310formed therein. FIG. 22 illustrates tissue 300 after it has beenbisected with a scalpel (not shown).

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, the components of thesurgical stapling device can be formed of any material suitable forsurgical use and having the required strength characteristics.Therefore, the above description should not be construed as limiting,but merely as exemplifications of preferred embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

1. A surgical stapling device comprising: a body having a pivotabletrigger; an approximation mechanism including at least one clamp slidemember, the approximation mechanism operably associated with the triggersuch that movement of the trigger from a non-compressed position to acompressed position effects movement of the at least one clamp slidemember distally from a retracted position to an advanced position; apawl member positioned adjacent the trigger and positioned to retain thetrigger in the compressed position subsequent to advancement of a thrustbar; a release mechanism including a release button and a releasemember, wherein the release button is positioned to effect movement ofthe at least one clamp slide member from the advanced position to theretracted position and the release member is positioned to engage thepawl member to facilitate movement of the trigger from the compressedposition to the non-compressed position; and a pin pusher, the pinpusher having a pair of legs, each leg having a contoured profile and arib extending therefrom, wherein the pin pusher has a reduced mass,thereby requiring a reduced actuation force to advance the pin pusherdistally.
 2. The surgical stapling device of claim 1, wherein therelease mechanism includes a biasing member that urges the releasebutton towards a first position.